In the car wash industry various expensive and complicated machines have been devised for washing automobiles. It has been found that something more than a high-pressure water spray is required to break the surface adhesion between dirt and the car's paint. Consequently, most mechanical systems have incorporated some form of brushes or wipers to brush off the dirt. The problem with such apparatus is that abrasives from the dirt accumulate on the brushes and the machines are incapable of providing the proper amount of pressure to all points of the car's surface in order to avoid damaging the paint surface with the abrasives that have accumulated in the brushes. Consequently, hand car washing is generally regarded as superior to machine washing.
The problem with hand car washing is it involves many steps, and generally takes about forty-five minutes per automobile. The car must first be wet with a hose, soaped up, wiped by hand, rinsed, and possibly rinsed again. Under most weather conditions the car must then be dried by hand to prevent disolved materials in the water from leaving spots on the car's finish when the water has air-dried.